Prevalence of and factors associated with nightmares in the elderly in a population based cohort study

Objectives: Nightmares are extremely unpleasant and vivid recurring dreams that are accompanied with awakening during sleep. However, earlier studies were mostly conducted with children and adults, with very few studies on nightmares in older adults. This population-based study aims to investigate the prevalence of nightmares and its associated factors nightmares in the elderly. Methods: This study utilized a subsample from the Korean Genome and Epidemiology Study (KoGES). Participants (n = 2940; mean age 63.71 ± 6.73) completed the questionnaires on nightmares (Disturbing Dream and Nightmare Severity Index; DDNSI), depression, suicidal ideation, sleep quality and stress. Results: Among the sample, 2.7% (n = 79) were classified into the nightmare group (NG), which was classified with DDNSI scores. In the age group over 70, prevalence of nightmares was 6.3% (n = 37), which was significantly higher than other age groups. Marital status, employment status and family income were associated with nightmares. Additionally, NG reported significantly more sleep problems, higher suicidal ideation, depression and stress compared to the non-nightmare group (N-NG). Logistic regression analyses results indicated that the NG was 4.35 times at higher risk for depression, and 3.16 higher risks for stress, and 3.45 higher risks for suicidal ideation compared to the N-NG after controlling for covariates. Conclusions: Our results indicate that psychological and demographic factors are associated with nightmares in the elderly. Furthermore, this population-based cohort study showed the prevalence of nightmares increased after age 70, which suggests the need for further studies of nightmares in older populations.